Biography of Hezron

Hezron is the older of the two sons of Pharez. He is among the youngest generation of the 70 Israelites to move to Egypt with Jacob:

Genesis 46

8. And these are the names of the children of Israel, which came into Egypt, Jacob and his sons: Reuben, Jacob's firstborn. 9 And the sons of Reuben; Hanoch, and Phallu, and Hezron, and Carmi. 10 And the sons of Simeon; Jemuel, and Jamin, and Ohad, and Jachin, and Zohar, and Shaul the son of a Canaanitish woman. 11 And the sons of Levi; Gershon, Kohath, and Merari. 12 And the sons of Judah; Er, and Onan, and Shelah, and Pharez, and Zarah: but Er and Onan died in the land of Canaan. And the sons of Pharez were Hezron and Hamul...

From Jewish Encyclopedia:

Hezron - son of Pharez and grandson of Judah, who was the direct ancestor of David (Gen. xlvi. 12; Ruth iv. 18). He had by his first marriage three sons: Jerahmeel; Ram, from whom David descended; and Caleb. Afterward he married the daughter of Machir, who bore him Segub, the father of Jair; and after his death his wife Abijah bore Ashur (I Chron. ii. 9, 21, 24).

by Emil G. Hirsch, M. Seligsohn